This invention relates to an apparatus and method for detecting leaks in containers. More particularly, it relates to an apparatus and method for detecting leaks in semirigid, plastic containers which method and apparatus is highly sensitive for detecting leaks yet is adaptable for various production rates.
Leak detection utilizing helium gas and mass spectrometers is well known and is described in the following U.S. Pat. Nos.: 2,486,199; 3,342,990; 3,247,373; 3,265,890; 3,277,295 and 3,690,151. The use of helium to detect leaks in particular vessels is also described in U.S. Pat. No. 3,949,596 and 3,520,176. Helium for use in a leak testing machine of the type concerned with in this invention is described in U.S. Pat. No. 3,914,983 whereas U.S. Pat. No. 3,729,984 describes an apparatus which is utilized in a high production rate for testing containers. In U.S. Pat. No. 3,729,983 a flushing-type gas is used in combination with a detector gas for purpose of leak detection.
In none of the foregoing prior art patents is there a high capacity machine illustrated which utilizes helium or another highly sensitive type gas for leak detection in an apparatus which can be utilized at a high production capacity. For example, U.S. Pat. Nos. 2,486,199; 3,342,990; 3,247,373; 3,265,890; 3,277,295 and 3,360,151 are all concerned with a basic leak detection system utilizing a spectrometer and helium gas. In U.S. Pat. Nos. 3,949,596 and 3,520,176 helium leak detection devices are described which would not lend themselves to leak detection on a mass production basis. While more rapid-rate-type testing units are described in U.S. Pat. Nos. 3,914,983 and 3,729,984, these units either are not adaptable to production rates of the type concerned with in this invention or do not utilize helium gas. The same is true concerning U.S. Pat. No. 3,729,983.
It is an advantage of the present invention to provide an apparatus and method for detecting leaks in containers at high production rates. Other advantages are an apparatus and method which is especially adapted to detecting leaks in semirigid containers composed of a plastic material; utilizes helium gas as a detection medium for maximum sensitivity; an apparatus which is modular in design and can be adapted to various production rates; an apparatus which utilizes open pocket members for fast placement and ejection of the containers for rapid testing procedure; an apparatus which can be readily adapted to various sized containers without extensive modification to the apparatus; and a machine which is highly sensitive to leak detection as an indication of the integrity of the container and its ability to maintain the contents in sterile condition.